• 한국산림과학회지
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• 제112권3호
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• pp.303-321
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• 2023

본 연구에서는 산림작업자의 작업강도를 비교하기 위한 산림작업부하지수(Forest Work Load Index, FWLI) 개발을 위해 숲가꾸기사업을 대상으로 산림작업부하지수 추정 연구를 실시하였다. FWLI는 근골격계 부담 분석방법 중 하나인 OWAS (Ovako Working Posture Analysis System)와 작업강도 분석방법 중 하나인 WLI (Work Load Index)를 이용하여 추정하는 방법을 개발하였다. OWAS는 작업자의 근골격계 부담 분석에 사용되는 대표적인 방법론이며, WLI는 작업자의 작업강도 분석에 사용되는 주요 방법이다. OWAS 기법을 통해 산출되는 사업종별 PRI값은 185.3(큰나무가꾸기), 150.6(가지치기), 181.1(산불예방숲가꾸기), 197.0(어린나무가꾸기)으로 분석되었으며, 측정된 심박수를 이용하여 산출되는 WLI값은 사업종별로 59.5%(큰나무가꾸기), 53.5%(가지치기), 56.2%(산불예방숲가꾸기), 62.3%(어린나무가꾸기)로 분석되었다. FWLI는 분석된 PRI와 WLI의 값을 이용하여 계산하였으며, 숲가꾸기 사업이 수행된 사업종별 FWLI값은 110.2(큰나무가 꾸기), 80.7(가지치기), 102.1(산불예방숲가꾸기), 123.0(어린나무가꾸기)으로 분석되었다. FWLI를 활용할 경우 세부공종부터 사업의 종류까지 다양하게 산림작업자의 작업부하를 정량적으로 비교할 수 있을 것으로 판단된다. 향후 연구목적에 따라 FWLI 분석의 범위(특정 작업, 작업자들의 역할, 특정 공정, 사업의 종류 등)를 정하여 작업자들에게 가해지는 부하를 측정해 작업자세의 개선 우선순위, 공종별 작업부하 비교, 사업종간 작업부하 비교를 통해 노임의 계상 및 품셈 등에 활용 할 수 있을 것으로 생각된다.

• 산업경영시스템학회지
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• 제24권69호
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• pp.51-64
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• 2001

A laboratory experiment was conducted to investigate the effects of working posture. work/rest ration, and task type on the physical workload in automobile assembly jobs. Ten healthy male university students participated as subjects in the experiment. East subject performed 18 experimental session with combination of 3 working posture 3 work/rest ratio and 2 task types. To examine the effect of various working conditions on workload, DMG analysis was performed on 4 different muscles in the neck an arm area, Also RPE scale and heart rate were taken as response variables. The result showed that all working conditions considered in the experiment had significant effects on the workload concluding that labor intensity in auto assembly jobs should be adjusted with respect to different levels of working posture, work/rest ratio, and task type. Detailed analysis are presented in the paper.

• 드라이브 ㆍ 컨트롤
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• 제10권2호
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• pp.30-36
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• 2013

Tractor is a farm vehicle that is designed to provide a high tractive effort at low speed. It is used for versatile agricultural tasks such as hauling a trailer, tillage, mowing and construction work. Most older tractors use a manual transmission. However, as the intensity of work increases, tractors equipped with automatic transmission become popular due to the work convenience. In order to give the operator a large degree of control in field work, 24 gears with automatic 8-speed and manual 3-speed are arranged in transmission. This paper deals with the gear train that is designed for 8-speed automatic transmission by the engagement of multi-disk clutches. The gear ratio for each speed as well as power transmission mechanism is analyzed through velocity analysis. In addition, constraints of mesh gear ratio are derived by investigating the power flow path in velocity diagram for the given 8-speed gear ratio.

• 한국산업보건학회지
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• 제31권2호
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• pp.156-172
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• 2021

Objectives: To investigate the trends of industrial injuries among long-term health care workers in Korea Methods: T7866 injuries were selected from the total industrial injuries approved by the Industrial Accident Compensation Insurance Act(Occupational Safety and Health Act) among long-term health care workers between 2007 and 2016 in Korea. We analyzied the trends of industrial injuries according to work process, occurrence type, and causes. Results: The industrial injuries among long-term health care workers increased since 2012. The mostly occurred area for industrial injuries were low back areas, which is related that the most serious industrial injuries occurred when the one long-term healthcare worker lift manually the recipient, from bed(ondol, Korean floor heating system) to a wheelchair, bed to bath bed, and wheelchair to bath chair. In addition to this, lack of workforce, increased work intensity due to overwork contributed the increasing of occupational injury. Conclusions: This study suggests that the main causes of industrial injuries were Lack of facilities and equipment for small private long-term care institutions, The physical load that goes into lifting the recipient directly, work intensity such as excessive workload and increased work speed. We suggest that the social publicization of long-term care service for the elderly, avoiding ways to lift recipients directly, introducing lifting machines as well as improving working methods, and reducing the workload of caregivers are required.

• STI Policy Review
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• 제9권1호
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• pp.77-98
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• 2018

In the past few decades, the importance of dynamics of University-Industry Linkage(UIL) in strengthening national and regional innovation competency and global competitiveness has been progressively more acknowledged. However, establishing an effective UIL for a better economic development is still a challenging endeavor in Ethiopia, particularly in Tigray region. This study is aimed at assessing the status of UIL and in order to achieve such aim it analyzed the determinants of firms' intensity of interaction with the Mekelle University (MU) and the effect of the intensity of interaction on the relevant firms' innovation performance. The findings of the study showed that the status of UIL between the firms and the university in Tigray region was at an infant stage. The study also found that firm size, firm age (startups) and government supports have had a significant effect on firms' intensity of interaction with the MU. However, the firms' intensity of interaction with the MU did not have any significant effect on the firms' innovation performance. In contrast, cooperation with customers, other groups and suppliers, firm size, firm age, and in-house R&D activities were found to have a significant effect on the firms' innovation performance. In conclusion, the acquisition of knowledge and technology from university does not have an important role in firms' innovation performance in the studied region. Consequently, the government should design effective strategies and assign responsible bodies to implement the strategies, create awareness, and organize both firms and university to meet and work together in order to enhance firms' innovation performance.

• Safety and Health at Work
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• 제12권3호
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• pp.384-389
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• 2021

Background: Social distancing by working-from-home is an effective measure to decrease the spread of COVID-19. However, this new work pattern could also affect the well-being of workers. Therefore, the aim of the study was to study the magnitude of occupational health problems and lifestyle changes among workers who have only recently started working from home. Methods: A cross-sectional study was conducted using online self-administered questionnaires during the coronavirus disease 2019 pandemic in the Bangkok metropolitan area, Thailand. The participants were from any organization that allowed working from home. The demographic data including the analysis of the characteristics of working from home, the occurrence of occupational health problems, and the lifestyle changes caused by working from home were analyzed. Results: A total of 869 workers were included as study participants. The highest prevalence of physical health problems among all workers was identified to be weight gain at a rate of 40.97% (95% confidence interval = 37.69-44.24), and the highest prevalence of psychosocial problems was identified to be cabin fever at a rate of 31.28% (95% confidence interval = 26.66-35.90%) among full-time working-from-home workers. The health effects that were significantly related to the intensity of working from home (p for trends <0.05), either positively or negatively, included body weight changes, ergonomic problems, indoor environmental problems, and psychosocial problems. Meanwhile, the lifestyle changes related to work intensity included eating pattern, sleep habits, and exercise. Conclusions: Working from home can affect workers' well-being in various aspects. Hence, occupational health providers must prepare for risk prevention and health promotion in this "new normal" working life pattern and for future pandemics.

• Journal of Korean Biological Nursing Science
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• 제14권4호
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• pp.268-274
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• 2012

Purpose: The purpose of this study was to examine the effects of self stretching on shoulder pain and should flexibility of nurses. Methods: Forty two nurses who work in a university hospital participated in the study; an intervention (n=22) and a control group (n=20). The nurses of intervention group carried out a 4-week self stretching program. All participants completed 1 item NRS scale for pain intensity and 1 item 4-Likert scale for pain intensity. Both shoulder flexibilities of the nurses were measured by back and reach test. All measurements were done at baseline, 2 week, 4 week during the program and 2 week following the program. The data was analyzed by frequency, percentage, ${\chi}^2$-test, t test, Repeated measures ANOVA using SPSS 12.0. Results: There were significant differences in the pain intensity (p<.001) and frequencies(p<.001) between two groups. Also, Left and right shoulder flexibilities of the intervention group significantly increased than those of the control group (p<.001 and p=.002 respectively). Conclusion: The results showed that self stretching reduce the intensity and frequency of shoulder pain and increase both shoulder flexibilities. Thus, self stretching is recommended as an intervention to improve shoulder function of hospital nurses.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.1-4
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• 2014

The present work focuses on the analysis of the pulverized coal combustion aerodynamics of the dual swirl burner by the control of the swirl-modes such as the outer swirl intensity (OSI). The detailed structure of pulverized coal swirling flames with swirl-mode was studied experimentally by particle image velocimetry and local flame colors based on $OH^*$, $CH^*$, and ${C_2}^*$ radicals. For all co-swirling conditions, the internal recirculation zone (IRZ) was observed near the inner shear layer with respect to the processing vortex core structure. Furthermore, a co-rotating vortex in the outer shear layer and the exhaust tube vortex (ETV) along the central axis were observed. The intensity of $CH^*$ signal was higher with small coal particle size, conversely, the size of the distribution of the $CH^*$ signal becomes larger. Therefore, the control of the aerodynamics with changing swirl intensities may play an important role in improving both environmental and combustion performances.

• Nuclear Engineering and Technology
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• 제53권3호
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• pp.911-919
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• 2021

In this paper, the design stress intensity values for the plate-type fuel assembly for research reactor are presented. Through a tensile test, the material properties of the cladding (aluminum alloy 6061) and structural material (aluminum alloy 6061-T6), in this case the yield and ultimate tensile strengths, Young's modulus and the elongation, are measured with the temperatures. The empirical equations of the material properties with respect to the temperature are presented. The cladding undergoes several heat treatments and hardening processes during the fabrication process. Cladding strengths are reduced compared to those of the raw material during annealing. Up to a temperature of 150 ℃, the strengths of the cladding do not significantly decrease due to the dislocations generated from the cold work. However, over 150 ℃, the mechanical strengths begin to decrease, mainly due to recrystallization, dislocation recovery and precipitate growth. Taking into account the uncertainty of the 95% probability and 95% confidence level, the design stress intensities of the cladding and structural materials are established. The presented design stress intensity values become the basis of the stress design criteria for a safety analysis of plate-type fuels.

• 산경연구논집
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• 제9권9호
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• pp.35-44
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• 2018

Purpose - In endless competition, companies pursue cost reduction and work efficiency. So, entrepreneurs try to increase job intensity, which may lead to job stress and high turnovers because of job burnout. But, Information systems are acknowledged as a work support tool that secures work convenience and the productivity of employees. In this study, we aimed to confirm the effects of information systems in reduing the work overload of employees in a human resource intensive industry. Research design, data and methodology - This is based on the job demands-resources model, conducting an empirical analysis of surveys given to hospital employees working in a human resource intensive industry. Results - The research revealed that information systems reduced the work overload of employees in a human resource intensive industry. Conclusion - This study confirmed the effects of information systems as a job resource based on JD-R theory, and presentation of empirical results indicated that information systems alleviate employee job overload and increases job satisfaction in the medical services industry. In the medical services industry, using electronic health record system decreases in work overload, which results in employees gaining time for self-development and time management, reducing job stress, and leading to job satisfaction.